Since the default value of sysctl_max_map_count is defined as
DEFAULT_MAX_MAP_COUNT from mm/util.c

    int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;

DEFAULT_MAX_MAP_COUNT is defined as 65530 (65535-5) in include/linux/mm.h

    #define MAPCOUNT_ELF_CORE_MARGIN        (5)
    #define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)

Signed-off-by: Fengfei Xi <xi.fengfei@h3c.com>
Link: https://lore.kernel.org/r/20201210082134.36957-1-xi.fengfei@h3c.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Document what a chain of Signed-off-by's in a patch commit message
should mean, explicitly.

This has been carved out from a tip subsystem handbook patchset by
Thomas Gleixner:

  https://lkml.kernel.org/r/20181107171010.421878737@linutronix.de



and incorporates follow-on comments.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20201217183756.GE23634@zn.tnic


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Renumber the steps in submit-checklist.rst as some numbers were skipped.

Signed-off-by: Milan Lakhani <milan.lakhani@codethink.co.uk>
Link: https://lore.kernel.org/r/1608064956-5512-1-git-send-email-milan.lakhani@codethink.co.uk


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

"it is a used" does not make sense.  Should be "it is used".

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201216134654.271508-1-lee.jones@linaro.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Commit 09028e60

 ("doc: zh_CN: add translatation for tmpfs") introduced
a cross reference without adding the appropriate target tag, leading to
this docs-build warning:

  Documentation/translations/zh_CN/filesystems/tmpfs.rst:5: WARNING: undefined label: tmpfs_index (if the link has no caption the label must precede a section header)

With automarkup, we don't actually need an explicit reference here at all,
so just take it out.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 09028e60

 ("doc: zh_CN: add translatation for tmpfs")
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The time has come to drop support for some truly ancient versions of
sphinx; put in a warning now.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

On the update of Sphinx version to 2.4.4, the "six" library won't be
installed automatically. (which is required by kfigure.py)

Main reason of this issue were occurred by the requirements changed from
the sphinx library. In Sphinx v1.7.9, six was listed on the
install_requires, but it has been removed since 2.x

The kfigure.py uses six library explicitly, adding six to
requirements.txt seems reasonable

Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20201208014628.GA1361@JSYoo5B-Base.localdomain


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Move the 'this section is a placeholder for now and needs help by
someone with domain knowledge' note one section upwards to the place
where it belongs: the 'Decode failure messages' section.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/d3894ba4a302beed661304cbcdc062c6dcfe3e58.1607489877.git.linux@leemhuis.info


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Here's a patch updating the meaning of TAINT_CPU_OUT_OF_SPEC after
Borislav introduced changes in a7e1f67e

 and upcoming patches in tip.

TAINT_CPU_OUT_OF_SPEC now means a bit more what it implies as the
flag isn't set just because of a CPU misconfiguration or mismatch.
Historically it was for SMP kernel oops on an officially SMP incapable
processor but now it also covers CPUs whose MSRs have been incorrectly
poked at from userspace, drivers being used on non supported
architectures, broken firmware, mismatched CPUs, ...

Update documentation and script to reflect that.

Signed-off-by: Mathieu Chouquet-Stringer <me@mathieu.digital>
Link: https://lore.kernel.org/r/20201202153244.709752-1-me@mathieu.digital


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add initial reset controller API documentation. This is mostly intended
to describe the concepts to users of the consumer API, and to tie the
kerneldoc comments we already have into the driver API documentation.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Amjad Ouled-Ameur <aouledameur@baylibre.fr>
Link: https://lore.kernel.org/r/20201201115754.1713-1-p.zabel@pengutronix.de


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Make various places which point to
Documentation/admin-guide/reporting-bugs.rst point to
Documentation/admin-guide/reporting-issues.rst instead. That document is
brand new and as of now is not completely finished. But even at this
stage it's a lot more helpful and accurate than reporting-bugs.rst.
Hence also add a note to reporting-bugs.rst, telling people they're
better off reading reporting-issues.rst instead.

reporting-bugs.rst is scheduled for removal once reporting-issues.rst
is considered ready.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/3df7c2d16de112b47bb6e6158138608e78562bf5.1607063223.git.linux@leemhuis.info


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add a mostly finished document describing how to report issues with the
Linux kernel to its developers. It is designed to be a lot more straight
forward and easier to follow than the current text about this
(Documentation/admin-guide/reporting-bugs.rst); at the same time the new
text should be more helpful for people unfamiliar with the topic, as it
provides a lot more details, too.

The main work on the text is done, but some polishing is still needed.
The text also needs to be reviewed by more people and a few issues still
might need some discussion. To make these tasks easier, it was decided
([1]) to add this document to the kernel sources in parallel to the
existing text; the latter will be removed once this text is considered
good enough(tm).

This document is quite long and provides a lot of details, but was
carefully crafted to make sure it's can also serve people that are in a
hurry. That's mainly achieved by having a TDLR and a step-by-step guide,
which should be good enough for quite a lot of people. Everybody that
wants or need more explanations can find them in a reference section,
which describes all the needed steps in detail.

Thanks to this structure the text can work for kernel developers that
just need to look something up, experienced FLOSS contributors that are
unfamiliar with the kernel's bug reporting workflow, and users reporting
something upstream for the first time. The text is thus a bit like the
kernel itself, which works well for embedded machines, a typical desktop
PC, cloud servers, and HPC.

The document was written in the hope it will improve the quality of the
bug reports, especially those that come from people unfamiliar with how
Linux kernel development works. Sadly quite a few reports from this
group are currently of poor quality and/or get submitted to the wrong
place. Part of the problem is the old reporting-bugs document, as it
makes its essence hard to grasp; it's and also inaccurate and slightly
outdated in a few spots. Due to this quite a few valid reports are
ignored in the end, which is annoying for those that compiled them and
bad for the kernel's quality.

The document near the top points out that it's still unfinished, but
nevertheless ready for consumption. Those few areas in the text that
might need some further discussion contain a note pointing this out.
Besides lack of review from core developers there is only one major
issue left: the section 'Decode failure message' is known to be
outdated: it's waiting for someone familiar with the topic to write
something up or give at least provide some hints and pointers what to
write there.

The new document is dual-licensed under GPL-2.0+ or CC-BY-4.0. The
latter is way more liberal and makes it attractive to use this text as a
base when writing about this topic on websites or in books. This
hopefully increases the chances that such texts are accurate and stick
to official way of doing things.

[1] https://lkml.kernel.org/r/20201118172958.5b014a44@lwn.net



Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e2db808f954744b79f10937a923d9c99bdca1fca.1607063223.git.linux@leemhuis.info


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add the full text of the CC-BY-4.0 license to the kernel tree as well as
the required tags for reference and tooling.

The license text was copied directly from the following url, but for
clarification a 'Creative Commons' was added before 'Attribution 4.0
International' in the first line:
https://creativecommons.org/licenses/by/4.0/legalcode.txt

CC-BY-4.0 is GPLv2 compatible, but when for example used for the
kernel's documentation it can easily happen that sphinx during
processing combines it with text or code from files using a more
restrictive license[1]. This bears pitfalls, hence point that risk out
and suggest to only use this license in combination with the GPLv2.

[1] https://lkml.kernel.org/r/20201201144314.GA14256@lst.de



Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Christoph Hellwig <hch@lst....

Fix thirty five typos in dm-integrity.rst, dm-raid.rst, dm-zoned.rst,
verity.rst, writecache.rst, tsx_async_abort.rst, md.rst, bttv.rst,
dvb_references.rst, frontend-cardlist.rst, gspca-cardlist.rst, ipu3.rst,
remote-controller.rst, mm/index.rst, numaperf.rst, userfaultfd.rst,
module-signing.rst, imx-ddr.rst, intel-speed-select.rst,
intel_pstate.rst, ramoops.rst, abi.rst, kernel.rst, vm.rst

Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com>
Link: https://lore.kernel.org/r/20201204072848.GA49895@spblnx124.lan


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Fixed twelve typos in cppc_sysfs.rst, binderfs.rst, paride.rst,
zram.rst, bug-hunting.rst, introduction.rst, usage.rst, dm-crypt.rst

Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com>
Reviewed-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20201204070235.GA48631@spblnx124.lan


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add missing ';' as well as fixes the indent for the first struct.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/20201207210027.1049346-1-ben.widawsky@intel.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This cleans up a few titles with extra colons, and removes the
reference to kernel 2.2. The docs don't yet cover *all* of 5.10 or
5.11, but I think they're close enough. Most entries are documented,
and have been checked against current kernels.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20201208074922.30359-1-steve@sk2.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The documentation refers to a non-existent 'struct synth_trace_state'
structure. The correct name is 'struct synth_event_trace_state'.

In other words, this patch is a mechanical substitution:
s/synth_trace_state/synth_event_trace_state/g

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20201104122113.322452-1-dedekind1@gmail.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

changeset ed13a92d

 ("docs: archis: add a per-architecture features list")
besides having a typo on its title, it was missing the feature file.

Add it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: ed13a92d

 ("docs: archis: add a per-architecture features list")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/e51c4692c4420d28bca35f553a9a3f3d78404d99.1607331056.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Auto-adjust the table columns width to better fit under
terminals, by breaking the description on multiple lines
and auto-estimating the minimal size for the
per-architecture status.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9d39ac3fd51f1360aecc328c01558be88a1d6930.1607095090.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Right now, arch compatibility is grouped by status at the
alphabetical order from A to Z, and then from a to z, e. g:.

	---
	TODO
	ok

Revert the order, in order to print first the OK results,
then TODO, and, finally, the not compatible ones.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/46d53d138eab8e4a55124323ceb5b212c6eedd08.1607095090.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Currently, there are too many white spaces at the tables,
and the information is very sparsed on it.

Make the format a lot more compact.

Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/8165ff379313e63a69898db19d790e4436224ffd.1607095090.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Changeset 6b80975c ("scripts: kernel-doc: fix typedef parsing")
added support for things like:

	typedef unsigned long foo();

However, it caused a regression on this prototype:

	typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);

This is only noticed after adding a patch that checks if the
kernel-doc identifier matches the typedef:

	./scripts/kernel-doc -none $(git grep '^.. kernel-doc::' Documentation/ |cut -d ' ' -f 3|sort|uniq) 2>&1|grep expecting
	include/media/v4l2-dv-timings.h:38: warning: expecting prototype for typedef v4l2_check_dv_timings_fnc. Prototype was for typedef nc instead

The problem is that, with the new parsing logic, it is not
checking for complete words at the type part.

Fix it by adding a \b at the end of each type word at the
regex.

fixes: 6b80975c

 ("scripts: kernel-doc: fix typedef parsing")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/218ff56dcb8e73755005d3fb64586eb1841a276b.1606896997.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Fix four typos in kcov.rst, sphinx.rst, clang-format.rst, and embargoed-hardware-issues.rst

Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20201202075438.GA35516@spblnx124.lan


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Fix two typos in kernel-docs.rst

Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20201202074938.GA35075@spblnx124.lan


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Change wording to say that messages are logged to the kernel log
buffer instead of to dmesg. dmesg is just one program that can
print the kernel log buffer.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20201202012409.19194-1-rdunlap@infradead.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Modify Coccinelle documentation to clarify usage of make command to
run coccicheck on a folder.

Changes in v2:
- Give example of folder instead of file
- Add note

Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Link: https://lore.kernel.org/r/20201126075730.w6brpeuviefmsxhl@adolin


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add a feature list matrix for each architecture to their
respective Kernel books.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9c39d4dd93e05c0008205527d2c3450912f029ed.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add a feature list matrix at the admin-guide.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f6c1e366fbc7ce1c9c94c7dc6c7852c6377cc0be.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The feature files have a special well-defined format. Add
a script that parses them, allowing to search for a feature
and/or by an architecture and to produce ReST-compatible
outputs.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/bb2e51e5aa883e2583a4a6280f1c1b391bd8ef4c.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add support for the same output format as the bash script,
and use its implementation instead of the previous one.

I opted to do such patch in order to have a single script
responsible for parsing Documentation/features and
produce different outputs.

As someone may rely on the past format, which is easy
to parse it, get_feat.pl now gains a new command with
the same output format as the previous script.

As a side effect, the perl script is a lot faster, as it reads
each file only once, instead of parsing files several times
via a for command and grep commands inside it.

This patch also changes the features list order to be
case-insensitive, in order to better match the output of
the existing script.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a97f49677805ad4e6b982d02c0db8c9dfbbd20a6.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Instead of producing a too wide table, let's split it per
subsystem, and use a better notation in order to make easier
for the reader to identify how a feature is supported on
multiple architectures.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9c3e8c813e8146c5c30e10fa75974f8fbfe6016a.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The Documentation/features contains a set of parseable files.
It is not worth converting them to ReST format, as they're
useful the way it is. It is, however, interesting to parse
them and produce output on different formats:

1) Output the contents of a feature in ReST format;

2) Output what features a given architecture supports;

3) Output a matrix with features x architectures.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/8b0c1ad06d689283a6d78c4ccd188a02c3acc0de.1606748711.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Document that /proc/PID/smaps shows PROT_MTE settings in VmFlags.
Support for this was introduced in

  commit 9f341931


  arm64: mte: Add PROT_MTE support to mmap() and mprotect()

Signed-off-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20201106101940.5777-1-szabolcs.nagy@arm.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Use full path to reference writing-schema.rst so that it becomes a
cross-reference.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20201123121333.59274-1-nfraprado@protonmail.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Sphinx 3.1 introduced namespaces for C cross-references. With this,
each C domain type/function declaration is put inside the namespace that
was active at the time of its declaration.

Add support for automatic cross-referencing inside C namespaces by
checking whether the corresponding source file had a C namespace Sphinx
directive, and if so, try cross-referencing inside of it before going to
the global scope.

This assumes there's only one namespace (if any) per rst file.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20201117021107.214704-1-nfraprado@protonmail.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The feature lists don't match reality as of v5.10-rc4, update them
accordingly (by features-refresh.sh).

Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20201119022709.45843-1-liwei391@huawei.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This is a Chinese translated version of
 Documentation/arm64/elf_hwcaps.rst

Signed-off-by: Bailu Lin <bailu.lin@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20201124023846.34826-1-bailu.lin@vivo.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

early_param memmap is only implemented on X86, MIPS and XTENSA. To avoid
wasting users’ time on trying this on platform like ARM, mark it clearly.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20201128195121.2556-1-song.bao.hua@hisilicon.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation: dev-tools: kasan.rst: fix typos

Signed-off-by: Andrew Klychkov <andrew.a.klyckov@gmail.com>
Link: https://lore.kernel.org/r/20201129192928.GA5692@ak-VirtualBox


Signed-off-by: Jonathan Corbet <corbet@lwn.net>